fix more linting issues

tests/test_graph.py

@@ -3,7 +3,6 @@ import os
 from pathlib import Path
 import pickle
 from typing import Type, Union
-from langflow import graph
 from langflow.graph.edge.base import Edge
 from langflow.graph.vertex.base import Vertex
 from langchain.agents import AgentExecutor
@@ -12,11 +11,9 @@ from langchain.chains.base import Chain
 from langchain.llms.fake import FakeListLLM
 from langflow.graph import Graph
 from langflow.graph.vertex.types import (
-    AgentVertex,
     FileToolVertex,
     LLMVertex,
     ToolkitVertex,
-    VectorStoreVertex,
 )
 from langflow.processing.process import get_result_and_thought
 from langflow.utils.payload import get_root_node